I have seen some ones around here that are friendly to people they know, but strangers are not taken too kindy too, and they get very nasty. Nasty is the stuff that comes out of them, too!
There's a video out there some place of geese attacking people, but the real bad ass in it is a black Swan that had gone after some guy years before, and when he comes back to the lake the Swan liives in 15 years after the original attack, he's barely out of the car before the Swan moves in for a repeat bout! It really works him over, and the Swan's Mrs. comes over towards the end and joins in on the fun. By the time he gets back into the car, he's bleeding and his pants are nearly torn off. Hilarious
They had a TV show about birds once and this guy went back to Japan after coming to the US , and the crane he had raised from birth saw him 30 years later, and instantly started doing this little dance thing they had done at the zoo 30 years before. The guy starts blubbering, and can't believe the bird remembers him after all that time.
My friend out west has a Hyacynth Macaw, and if I'm put on a speakerphone, and talk to the bird, he starts barking like my old dog used to, and even says a distorted version of me yelling, "Hey, knock it off!" The bird, 51 years old, hasn't seen me since 1982!